In turbine engines, compressed air discharged from a compressor section and fuel introduced from a source of fuel are mixed together and burned in a combustion section, creating combustion products defining hot combustion gases. The combustion gases are directed through a hot gas path in a turbine section, where they expand to provide rotation of a turbine rotor. The turbine rotor is linked to a shaft to power the compressor section and may be linked to an electric generator to produce electricity in the generator.
One or more conduits such as combustor liners are typically used for conveying the combustion gases from one or more combustor assemblies located in the combustion section to the turbine section. Due to the high temperature of the combustion gases, the combustor liner typically requires cooling during operation of the engine to avoid overheating. Prior art solutions for cooling include supplying a cooling fluid, such as air that is bled off from the compressor section, onto an outer surface of the combustor liner to provide direct convection cooling. An impingement member or impingement sleeve may be provided about the outer surface of the liner, wherein the cooling fluid may flow through small holes formed in the impingement member before being introduced onto the outer surface of the liner. Other prior art solutions inject a small amount of cooling fluid along an inner surface of the liner to provide film cooling to the inner surface.
Damping devices such as resonator boxes may be used to suppress or absorb acoustic energy generated during engine operation. Conventional configurations utilize a combustor liner with acoustic metering holes arranged in a uniform, evenly spaced pattern that equalizes the axial and circumferential distance between each hole. For example, metering holes organized in a rectangular and or axially staggered rectangular pattern can provide an acoustic path between an interior of the resonator boxes and a combustion chamber surrounded by the combustor liner, as well as provide a path for cooling air to cool the combustor liner in an area of the resonator boxes.